Abstract: A resonance device is provided that includes a resonator including a base, a plurality of vibration arms having arms on a fixed end side connected to the base and weight portions on an open end side. A frame is around a periphery of the vibration arms and holds the base. The vibration arms extending parallel to each other and vibrating in an out-of-plane bending vibration mode as a main vibration. A lower cover and an upper form a vibration space for the resonator. A protrusion protrudes into the vibration space from an inner surface of the lower or upper cover. The frame has projections formed in positions facing the weight portions in a plan view.

Abstract: The present invention relates to a method for producing a platinum-based alloy powder, the method comprising a heat treatment of a mixed powder containing a platinum-based powder composed of at least one selected from the group consisting of platinum and platinum compound, a platinum group metal-based powder composed of at least one selected from the group consisting of iridium, rhodium, palladium, and compound containing at least one of them, and an alkaline-earth metal compound, wherein specific surface area of the platinum group metal-based powder is 30 m2/g or more and D90 of the mixed powder is 1.0 ?m or less. According to the method for producing a platinum-based alloy powder of the invention, it is possible to produce a platinum-based alloy powder that has a desired particle diameter, also has a sharp particle size distribution, and has high purity and crystallinity.

Abstract: The present invention relates to a method for producing a platinum-based alloy powder, the method comprising a heat treatment of a mixed powder containing a platinum-based powder composed of at least one selected from the group consisting of platinum and platinum compound, a platinum group metal-based powder composed of at least one selected from the group consisting of iridium, rhodium, palladium, and compound containing at least one of them, and an alkaline-earth metal compound, wherein specific surface area of the platinum group metal-based powder is 30 m2/g or more and D90 of the mixed powder is 1.0 ?m or less. According to the method for producing a platinum-based alloy powder of the invention, it is possible to produce a platinum-based alloy powder that has a desired particle diameter, also has a sharp particle size distribution, and has high purity and crystallinity.